MCP4725

DS22039C-page 18

© 2007 Microchip Technology Inc.

TABLE 6-2:

WRITE COMMAND TYPE

FIGURE 6-1:

Write Command for Fast Mode.

C2 C1 C0

Command Name

Function

0

0

X

Fast Mode

This command is used to change the DAC register. EEPROM is not affected

00

X

“

“

0

1

0

Write DAC Register

Load configuration bits and data code to the DAC Register

0

1

1

Write DAC Register

and

EEPROM

(a) Load configuration bits and data code to the DAC Register

and

(b) also write the EEPROM

1

0

0

Reserved

Reserved for future use

1

0

1

Reserved

Reserved for future use

1

1

0

Reserved

Reserved for future use

1

1

1

Reserved

Reserved for future use

Note 1: X = Dont’ Care. Fast Mode does not use C0 bit.

2: The MCP4725 ignores the “Reserved” commands.

1st byte (Device Addressing)

Device Code

Address

R/W

ACK (

MCP4725)

2nd byte

3rd byte

DAC Register Data (12 bits)

ACK (

MCP4725)

Repeat bytes of 2nd and 3rd bytes

Change DAC Code in Fast Mode: (C2,C1) = (0,0)

Fast Mode Command (C2, C1 = 0, 0)

ACK (

MCP4725)

Power Down Select

Start Bit

2nd byte

3rd byte

Read/Write Command

Stop Bit

Stop Bit

see

Note 1

see

Note 2

ACK (

MCP4725)

see

Note 2

Note 1: A2 and A1 bits are programmed at the factory by hard-wired, and A0 bit is determined by the logic state

of A0 pin.

2: The device updates V

11

0

0 A2

0

A1 A0

00 PD1 PD0 D11

D8

D10 D9

D7 D6 D5 D4 D3

D0

D2 D1

00 PD1 PD0 D11

D8

D10 D9

D7 D6 D5 D4 D3

D0

D2 D1

Bits

ACK (

MCP4725)